The invention relates to a modular endoprosthesis, particularly a femur prosthesis, which has a conical socket connection, with a first shaft element having a substantially conical bore, a second shaft element having a substantially conical pin adapted to fit the bore in the first shaft element, for connecting the two shaft elements together, wherein the first shaft element containing the bore has a circumferential indentation on its outer wall, close to the mouth end, for the purpose of reducing the mechanical load occurring on the edge of the mouth of the bore under bending stress.
DE 33 40 767 A1 discloses a prosthesis of this kind which consists of at least two shaft portions connected by fitting together. The mechanical connection between two shaft elements is achieved here by pressing a conical pin formed on one shaft element into a conical bore provided in the other shaft element so as to obtain a press fit.
As the endoprosthesis is made up of different shaft elements, endoprostheses of different shaft lengths can advantageously be produced in this way.
Moreover, the endoprosthesis can easily be removed, for example in the case of a repeat operation, by separating the shaft elements from one another and removing them one by one.
A disadvantage of the known endoprosthesis is, however, that the shaft element which contains the conical socket may have pronounced wear caused by microscopic movements in the region of the rim of the mouth, which may lead to cracking in extreme cases.